| Message ID | 20230203162353.34876-1-alexandru.elisei@arm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | arm: Add PSCI CPU_OFF test | expand |
On Fri, Feb 03, 2023 at 04:23:51PM +0000, Alexandru Elisei wrote: > The series adds a test for the PSCI function CPU_OFF. The test is > implemented in patch #2, "arm/psci: Add PSCI CPU_OFF test case". Patch #1, > "arm/psci: Test that CPU 1 has been successfully brought online" is a > preparatory patch to allow the CPU_OFF test to run after the CPU_ON test. > Executing the CPU_OFF test after the CPU_ON test makes the most sense, > since CPU_OFF requires all the CPUs to be brought online before the test > can execute, and this is exactly what the CPU_ON test does. > > I believe that proving that a CPU has been successfully offlined is an > undecidable problem - it might just be that the CPU is stuck at a higher > exception level doing something else entirely, and if the test were to wait > long enough, the CPU would return from the CPU_OFF call and start executing > code, thus failing to be offlined. Right now, the test waits for 100ms > after checking that all the other CPUs are offline. I thought this was a > good balance between making the test fast and being reasonably sure that > the offline succeeded. I'm open to suggestions here if anyone thinks > otherwise. > > Tested for both the arm and arm64 architectures: on an x86 machine (qemu > with TCG), and a rockpro64 (qemu and kvmtool). > > And Nikita is not longer at Arm, and I don't have a new email address where > she can be reached, so I didn't CC her. > > Changelog: > > v5 -> v6: > - Added Reviewed-by tag to #1 (Drew). > - Fixed the unintended change that added the argc/argv arguments to main() > in #2 (Drew). > - Fixed bailing early when all secondaries are offline in #2 (Drew). > - Run the cpu-off test only if some of the secondaries are not idling > instead if cpu-on has failed (cpu-on can fail for other reasons too) > (Drew). > > v4 -> v5: > - Open code smp_prepare_secondary in psci.c instead of exposing it as a > library function in the cpu_on test (Drew). > - Don't return early if a CPU failed to online CPU1 in the cpu_on test, and > check the return values for the CPUs that succeeded to online CPU 1 > (Drew). > - Drop cpu_off_success in the cpu_off test in favour of checking > AFFINITY_INFO and the cpu idle mask (Drew). > - Hopefully made the cpu_off test faster (Drew). > > v3 -> v4: > - Moved ownership of the series to Alexandru Elisei. All bugs are mine. > - Moved the timeout for the CPU_ON test to patch #1. > - Changed the include order for arm/psic.c in patch #1 to order the headers > alphabetically. > - Run the CPU_OFF test only if CPU_ON succeeds, because CPU_OFF expects all > CPUs to be online, the test would otherwise hang forever. > - Minor style changes here and there. > > v2 -> v3: > - Add timeout so that test does not hang if CPU1 fails to come online > - Remove unnecessary call of on_cpus() in the condition where target CPU is not online. > > v1 -> v2: > - Modify PSCI CPU_ON test to ensure CPU 1 remains online after the execution of the test. > - Addition of PSCI CPU_OFF test and calling it after PSCI CPU_ON test has been executed. > > Alexandru Elisei (1): > arm/psci: Test that CPU 1 has been successfully brought online > > Nikita Venkatesh (1): > arm/psci: Add PSCI CPU_OFF test case > > arm/psci.c | 138 +++++++++++++++++++++++++++++++++++++++++----- > lib/arm/asm/smp.h | 9 ++- > lib/arm/smp.c | 4 -- > lib/errata.h | 2 + > 4 files changed, 134 insertions(+), 19 deletions(-) > > > base-commit: 2480430a36102f8ea276b3bfb1d64d5dacc23b8f > -- > 2.39.1 > Applied, thanks